Scottsdale, Ariz. -- Exactly one month ago, Brandon Moss became the everyday first baseman for the A's, whose Feb. 4 trade that sent Chris Carter to the Astros left him as the undisputed No. 1 guy.

Still, Moss claims he's no more at ease despite shedding his platoon status.

"I wouldn't call it a comfort factor. I went into spring training one other time thinking the job was mine," Moss said Sunday. "Never assume anything's yours."

He was referring to 2009 with the Pirates. It's the most he played in a big-league season, but his 385 at-bats were far fewer than he had anticipated. He was part of a "four- or five-man rotation in right field," he said, sharing time with Garrett Jones, Delwyn Young and Eric Hinske, among others.

Now the A's envision Moss, following his breakout 2012, as the man at first, facing both right-handed and left-handed pitchers. A lefty swinger, Moss actually hit for a higher average against lefties last year, following his career path.

But his power numbers are far better against righties - .643 slugging percentage vs. .431 off lefties - which is why the A's value him so highly. They're perfectly fine with him as a dead pull hitter with an all-or-nothing mentality and admitting he's not in this business to hit singles, especially against righties.

"I don't drive the ball as well against lefties," Moss said. "I'm more of a hitter against them as opposed to a power hitter. I know how to hit them. I've always hit them well. They don't intimidate me at all."

A year ago, Moss was in camp with a minor-league contract and played with Triple-A Sacramento until June, when he arrived with the A's and put on a historic power display with 21 homers, the third most all time by an American Leaguer appearing in fewer than 90 games.

It's a far cry from Moss' days with the Red Sox, Pirates and Phillies, for whom he hit 15 homers in 249 games. He said the A's took a different course from other clubs, accepting him as a free swinger rather than trying to turn him into a contact hitter who sprays the ball to all fields.

"No one really wanted to see what it was I did well," Moss said. "They want you to do the, quote unquote, right thing. Hit line drives. Hit the ball the other way. Put the ball in play. My swing doesn't work that way. Chili gave me confidence. It was no longer about being somebody else, but about me being who I was."

Moss doesn't necessarily strive for a high on-base percentage, but his OBP last year was an impressive .358. Considering he hit a league-high .545 (18-for-33) on first pitches, it's clear he's not in the Daric Barton/Jack Cust mold of being open-minded about drawing walks.

On that front, Moss suggests that OBP, a stat once closely associated with the A's thinking, isn't at the forefront for this team.

"I don't think this team is all about on-base percentage. I think that's a misconception. They're about runs and scoring runs," Moss said. "Look at our 3-4-5 guys (Josh Reddick, Yoenis Céspedes, Moss). All three of us are free swingers. We walk some, strike out a good bit. Nobody's up there trying to take a walk. Everyone's up there to hit, do some damage."

Moss converted from the outfield last year and said he didn't take a single grounder at first base in spring training. Now he's taking plenty every day and said he's better "by leaps and bounds" because he's getting a chance to learn footwork and technique.

That's certainly a plus. But the reason Carter was traded, and the reason the A's want Moss in the lineup, is his work at the plate.

This year, Moss will get a chance to do more, a chance to play more regularly, even if he wouldn't call it a comfort factor.